Truth be told , 100 - 200 year old farmhouse attics and barns are good places to explore.

I bought the remants of a baroque cello made by N Amati found in a barn in Maine.
It is real but only 80% there. I restored it until it became stable. Today it is the only one I play due to the ease of the stings and slightly smaller size.

My mom found 100 lbs of sheet music of the civil war through to the 1930s in our farmhouse attic. Lots and lots of old fashioned photos.